Method for producing hexafluoropropene

Abstract

Disclosed is a method for producing hexafluoropropene, with which a product containing hexafluoropropene is obtained by bringing a compound (A) represented by formula (A) into contact with at least one compound (B) that is selected from the group consisting of octafluorocyclobutane, pentafluoroethane, octafluoro-1-butene, and octafluoro-2-butene, and subsequently heating the resultant mixture at a reaction temperature of 780°C or higher in a reactor. In formula (A), X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.　(A): CHF2-X

Description

Method for producing hexafluoropropene

[0001] This disclosure relates to a method for producing hexafluoropropene.

[0002] Hexafluoropropene is a compound used as a raw material for fluororesins and the like. Hexafluoropropene can be obtained, for example, by the thermal decomposition reaction of fluorine-containing compounds such as trifluoromethane and chlorodifluoromethane. Hereinafter, hexafluoropropene will also be referred to as "HFP," trifluoromethane as "R23," and chlorodifluoromethane as "R22." For example, Patent Document 1 discloses a method for producing a mixture of tetrafluoroethylene and HFP by the thermal decomposition reaction of R23, and obtaining high-purity tetrafluoroethylene and HFP, respectively, by purification. Hereinafter, tetrafluoroethylene will also be referred to as "TFE."

[0003] Chinese Patent Application Publication No. 107216233 Specification

[0004] When HFP is produced using the thermal decomposition reaction of the fluorine-containing compound mentioned above as the main reaction, various by-products may be generated in addition to the target compound, HFP. Therefore, there is a need to suppress the amount of by-products generated and produce HFP efficiently.

[0005] One aspect of this disclosure aims to provide a method for producing hexafluoropropene with high efficiency.

[0006] This disclosure includes the following embodiments: <1> A method for producing hexafluoropropene, comprising contacting a compound (A) represented by the following formula (A) with a compound (B) which is at least one selected from the group consisting of octafluorocyclobutane, pentafluoroethane, octafluoro-1-butene, and octafluoro-2-butene, and heating the resulting mixture in a reactor at a reaction temperature of 780°C or higher to obtain a product containing hexafluoropropene. (A) CHF ２-X In formula (A), X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. <2> The method for producing hexafluoropropene according to <1>, wherein the post-contact mixture is a mixture obtained by contacting compound (A) with tetrafluoroethylene and compound (B). <3> The method for producing hexafluoropropene according to <1> or <2>, wherein the post-contact mixture is a mixture obtained by contacting compound (A) with tetrafluoroethylene, compound (B) and nitrogen. <4> The method for producing hexafluoropropene according to any one of <1> to <3>, wherein compound (A) includes at least one selected from the group consisting of chlorodifluoromethane and trifluoromethane. <5> The method for producing hexafluoropropene according to any one of <1> to <4>, wherein compound (A) is trifluoromethane and compound (B) is at least one selected from the group consisting of octafluorocyclobutane and pentafluoroethane. <6> A method for producing hexafluoropropene according to any one of <1> to <5>, wherein compound (A) is trifluoromethane and compound (B) is octafluorocyclobutane and pentafluoroethane. <7> A method for producing hexafluoropropene according to any one of <1> to <5>, wherein compound (A) is trifluoromethane and compound (B) is pentafluoroethane. <8> A method for producing hexafluoropropene according to any one of <1> to <5>, wherein compound (A) is trifluoromethane and compound (B) is octafluorocyclobutane. <9> A method for producing hexafluoropropene according to any one of <1> to <8>, wherein the post-contact mixture is preheated at a mixture preheating temperature of less than 780°C, and then heated in the reactor at the reaction temperature. <10> A method for producing hexafluoropropene according to <9>, wherein the mixture preheating temperature is 100 to 750°C. <11> A method for producing hexafluoropropene according to any one of <1> to <10>, wherein the compound (A) is preheated to a first preheating temperature of less than 780°C before contact. <12> A method for producing hexafluoropropene according to <11>, wherein the first preheating temperature is 100 to 750°C.<13> A method for producing hexafluoropropene according to <11> or <12>, wherein, before the contact, compound (A) preheated at the first preheating temperature is mixed with a second preheating heat medium heated at a second preheating heat medium heating temperature that is higher than the first preheating temperature but less than 780°C to form a second post-preheated mixture. <14> A method for producing hexafluoropropene according to any one of <1> to <10>, wherein, before the contact, compound (B) is preheated at a compound (B) preheating temperature of 100 to 350°C. <15> A method for producing hexafluoropropene according to <11> or <12>, wherein, before the contact, compound (B) is preheated at a compound (B) preheating temperature of 100 to 350°C. <16> A method for producing hexafluoropropene according to <13>, wherein, before the contact, compound (B) is preheated at a compound (B) preheating temperature of 100 to 350°C. <17> The method for producing hexafluoropropene according to any one of <1> to <16>, wherein the reaction temperature is 800 to 1000°C. <18> The method for producing hexafluoropropene according to any one of <1> to <17>, wherein the heating time at the reaction temperature is 2 seconds or less. <19> The method for producing hexafluoropropene according to any one of <1> to <18>, wherein the reactor is not filled with catalyst.

[0007] According to one aspect of this disclosure, a method for producing hexafluoropropene with high hexafluoropropene production efficiency is provided.

[0008] This is a schematic diagram showing an example of a manufacturing apparatus used in the manufacturing method of the present disclosure. This is a schematic diagram showing another example of a manufacturing apparatus used in the manufacturing method of the present disclosure. This is a schematic diagram showing another example of a manufacturing apparatus used in the manufacturing method of the present disclosure. This is a schematic diagram showing another example of a manufacturing apparatus used in the manufacturing method of the present disclosure. This is a schematic diagram showing another example of a manufacturing apparatus used in the manufacturing method of the present disclosure.

[0009] The embodiments of this disclosure are described in detail below. However, this disclosure is not limited to the embodiments described below. In the embodiments described below, the components (including elemental steps, etc.) are not essential unless otherwise explicitly stated. The same applies to numerical values ​​and their ranges, and do not limit this disclosure.

[0010] In this disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that are not clearly distinguishable from other processes, provided that their purpose is achieved. In this disclosure, numerical ranges indicated using "~" include the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Also, in numerical ranges described in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the value shown in the example. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the substance corresponding to each component are present in the composition, the proportion of each component means the total proportion of the multiple types of substances present in the composition, unless otherwise specified. When embodiments are described in this disclosure with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Also, the sizes of the members in each figure are conceptual, and the relative relationships of the sizes between members are not limited thereto. Furthermore, components with substantially the same function may be assigned the same reference numeral throughout all drawings, and redundant explanations may be omitted.

[0011] In this disclosure, “preheating” means heating at least one of compound (A) and compound (B) before supplying them to the reactor. Preheating of at least one of compound (A) and compound (B) is performed in a location other than inside the reactor. During the preheating of at least one of compound (A) and compound (B), a small amount of at least one of compound (A) and compound (B) may undergo a thermal decomposition reaction. Furthermore, during the preheating of the post-contact mixture before supplying it to the reactor, some reaction between the thermal decomposition products of compound (A) and compound (B) may proceed. In this disclosure, “reactor” means a region heated to a reaction temperature of 780°C or higher, where the reaction that produces HFP mainly proceeds. In this disclosure, “preheating temperature,” “reaction temperature,” and “heating temperature” are set temperatures for heating, and at least a portion of the heated material may be at a temperature different from the above set temperature. In this disclosure, “by-products” means products other than the target product, HFP.

[0012] [Method for Producing Hexafluoropropene (HFP)] A method for producing hexafluoropropene (HFP) in one embodiment of the present disclosure includes contacting a compound (A) represented by the following formula (A) with a compound (B) which is at least one selected from the group consisting of octafluorocyclobutane, pentafluoroethane, octafluoro-1-butene, and octafluoro-2-butene, and heating the resulting mixture in a reactor at a reaction temperature of 780°C or higher to obtain a product containing HFP. (A) CHF ２ -X In formula (A), X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. Hereinafter, octafluorocyclobutane will also be referred to as "C318", pentafluoroethane as "R125", octafluoro-1-butene as "FO-1318cyc", and octafluoro-2-butene as "FO-1318myy".

[0013] The manufacturing method of this embodiment includes a contact step of contacting compound (A) and compound (B) to obtain a post-contact mixture, a supply step of supplying compound (A) and compound (B) into a reactor, and a reaction step of heating the post-contact mixture in the reactor at a reaction temperature of 780°C or higher to obtain a product containing HFP. The order of the above contact step and supply step is not particularly limited. Specifically, compound (A) and compound (B) may be supplied separately into the reactor and then brought into contact in the reactor, or the post-contact mixture obtained by contacting compound (A) and compound (B) may be supplied into the reactor. In other words, in the manufacturing method of this embodiment, the supply step may be followed by the contact step, or the contact step may be followed by the supply step.

[0014] According to the manufacturing method of this embodiment, the efficiency of HFP production is higher compared to the case where HFP is produced using the thermal decomposition reaction of compound (A) alone as the main reaction. The reason for this is not clear, but it is presumed to be as follows. When HFP is obtained using the thermal decomposition reaction of compound (A) alone as the main reaction, HFP is produced through a first step in which tetrafluoroethylene (TFE) is produced as a reaction intermediate by a bimolecular reaction between difluorocarbenes, which are thermal decomposition products of compound (A), and a second step in which the produced TFE and the difluorocarbenes, which are thermal decomposition products of compound (A), react further. When HFP is produced using the thermal decomposition reaction of compound (A) alone as the main reaction, by-products other than TFE are likely to be produced in the first step. Also, when HFP is produced using the thermal decomposition reaction of compound (A) alone as the main reaction, difluorocarbenes are consumed by the bimolecular reaction, and while a large amount of TFE is produced, the amount of difluorocarbene decreases, resulting in a smaller amount of HFP produced. Therefore, it is possible that the selectivity for the final target compound, HFP, that is, the proportion of HFP in the total product, will be low.

[0015] In contrast, in this embodiment, HFP is produced by heating a post-contact mixture, obtained by contacting compound (A) and compound (B), in a reactor at a reaction temperature of 780°C or higher. When the post-contact mixture is heated at the above reaction temperature, difluorocarbene is produced by the thermal decomposition reaction of compound (A), and TFE is produced by the thermal decomposition reaction of compound (B). HFP is then produced by the reaction of the produced TFE with the difluorocarbene. In the thermal decomposition reaction of compound (B), compounds other than TFE are less likely to be produced compared to when the thermal decomposition reaction of compound (A) alone is the main reaction. In addition, the presence of TFE, a thermal decomposition product of compound (B), suppresses the bimolecular reaction between difluorocarbenes and promotes the production of HFP by the reaction of TFE with difluorocarbene. As a result, the selectivity for the final target compound, HFP, is also increased, and it is presumed that the HFP production efficiency, that is, the ratio of the amount of HFP produced to the total amount of raw materials consumed, will also be higher. Furthermore, compound (B) is less prone to disproportionation reactions than TFE, and is easier to transport and handle. Therefore, the manufacturing method of this embodiment has the advantage of being easier to implement compared to the case where only TFE is used instead of compound (B).

[0016] [Components contained in the mixture after contact] First, the components contained in the mixture after contact will be explained. Here, the "mixture after contact" is a mixture obtained by contacting compound (A) and compound (B), as described above. The mixture after contact contains at least compound (A) and compound (B), and may also contain components other than compound (A) and compound (B).

[0017] <Compound (A)> Compound (A) used in the manufacturing method of this embodiment may be any compound represented by the following formula (A), and only one compound represented by the following formula (A) may be used, or two or more may be used in combination. (A) CHF ２-X In formula (A), X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. Compound (A) preferably contains at least one compound selected from the group consisting of R22 and R23 from among the compounds represented by formula (A) above, from the viewpoint of improving the efficiency of HFP production, and more preferably R22 or R23, and even more preferably R23.

[0018] <Compound (B)> Compound (B) used in the manufacturing method of this embodiment is at least one selected from the group consisting of C318, R125, FO-1318cyc, and FO-1318myy. Compound (B) may be used alone or in combination of two or more. From the viewpoint of improving the efficiency of HFP production, compound (B) preferably contains at least one selected from the group consisting of C318 and R125, more preferably contains C318, and even more preferably contains C318. Furthermore, from the viewpoint of suppressing the production of 1,2,3,3,3-pentafluoropropene (hereinafter also referred to as "R1225ye") among the by-products, compound (B) preferably contains R125, and even more preferably contains R125. Furthermore, compound (B) preferably contains at least one compound selected from the group consisting of C318 and R125, and more preferably C318 and R125, from the viewpoint of balancing the improvement of HFP production and the suppression of R1225ye production.

[0019] <Combinations of Compound (A) and Compound (B)> Examples of combinations of Compound (A) and Compound (B) include combinations of R23 and C318, combinations of R22 and C318, combinations of R23 and R125, combinations of R22 and R125, and combinations of R23, C318, and R125. From the viewpoint of improving the efficiency of HFP production, a combination of Compound (A) and Compound (B) consisting of at least one selected from the group consisting of R22 and R23 and at least one selected from the group consisting of C318 and R125 is preferred, a combination of R23 and C318 and a combination of R23, C318, and R125 are even more preferred, and a combination of R23 and C318 is particularly preferred. Furthermore, from the viewpoint of suppressing the formation of R1225ye among the by-products, the combination of compound (A) and compound (B) is preferably R23 and R125, and the combination of R23 and C318 and R125, with the combination of R23 and R125 being more preferred. Moreover, from the viewpoint of balancing the improvement of HFP production and the suppression of R1225ye formation, the combination of compound (A) and compound (B) is preferably a combination of R23 and at least one selected from the group consisting of C318 and R125, with the combination of R23 and C318 and R125 being more preferred.

[0020] The ratio of compound (A) to compound (B) to be brought into contact is not particularly limited. For example, the ratio of compound (B) to the total amount of compound (A) and compound (B) to be brought into contact can be 1 to 50 mol%, preferably 5 to 30 mol%, and more preferably 5 to 15 mol%. A ratio of compound (B) above the lower limit results in a higher amount of HFP production. On the other hand, a ratio of compound (B) below the upper limit has the advantage of suppressing the production of by-products other than TFE.

[0021] <TFE> The post-contact mixture preferably contains TFE in addition to compound (A) and compound (B). The post-contact mixture is preferably a mixture obtained by contacting compound (A), TFE, and compound (B). The further inclusion of TFE in the post-contact mixture increases the efficiency of HFP production. In addition, the inclusion of compound (A), TFE, and compound (B) in the post-contact mixture suppresses the generation of by-products compared to the case where compound (B) is not included.

[0022] Furthermore, in the contact between compound (A), TFE, and compound (B), the order of contact is not particularly limited. Compound (A), TFE, and compound (B), each contained in a separate container, may be brought into contact simultaneously. A mixture of compound (A) and TFE may be brought into contact with compound (B), or a mixture of TFE and compound (B) may be brought into contact with compound (A). Additionally, the contact between compound (A), TFE, and compound (B) may involve bringing a mixture of compound (A) and TFE contained in the same container into contact with compound (B) contained in a different container, or a mixture of compound (B) and TFE contained in the same container into contact with compound (A) contained in a different container.

[0023] When the post-contact mixture is a mixture obtained by contacting compound (A), TFE, and compound (B), the ratio of TFE to the total amount of compound (A) and TFE to be contacted can be, for example, 20 mol% or less, and from the viewpoint of improving the efficiency of HFP production and suppressing the generation of by-products, 3 to 18 mol% is preferred, and 5 to 12 mol% is more preferred. Also, when the post-contact mixture is a mixture obtained by contacting compound (A), TFE, and compound (B), the ratio of TFE to the total amount of TFE and compound (B) to be contacted can be, for example, 91 mol% or less, and from the viewpoint of improving the efficiency of HFP production and suppressing the generation of by-products, 20 to 80 mol% is preferred, and 40 to 60 mol% is more preferred. Furthermore, when the mixture after contact is a mixture obtained by contacting compound (A), TFE, and compound (B), the ratio of TFE to the total amount of compound (A), TFE, and compound (B) to be contacted can be, for example, 18 mol% or less, and from the viewpoint of improving the efficiency of HFP production and suppressing the generation of by-products, 2 to 15 mol% is preferred, and 4 to 11 mol% is more preferred.

[0024] <Nitrogen> The post-contact mixture preferably contains nitrogen in addition to compound (A) and compound (B), and more preferably contains TFE and nitrogen in addition to compound (A) and compound (B). The post-contact mixture is preferably a mixture obtained by contacting compound (A), compound (B), and nitrogen, and more preferably a mixture obtained by contacting compound (A), TFE, compound (B), and nitrogen. Nitrogen is included in the post-contact mixture, for example, as a "medium" as described later. In this embodiment, "medium" is a general term for the first preheating heat medium, dilution medium, second preheating heat medium, and contact heat medium, as described later. The nitrogen included in the post-contact mixture may be preheated or unheated. Specific examples of the medium include nitrogen, as well as inert gases such as helium and argon. By including a medium in the post-contact mixture, the HFP concentration inside the reactor is lower compared to the case where no medium is included, which has the advantage of suppressing the generation of sequential reaction by-products derived from HFP, and also has the advantage of suppressing the formation of hot spots associated with the reaction because the raw material concentration is lower. Furthermore, the presence of nitrogen in the post-contact mixture offers the advantage of lower HFP production costs compared to cases where only other media are present. When the post-contact mixture contains nitrogen, the proportion of nitrogen in the total media contained in the post-contact mixture is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and most preferably 100 mol% from the viewpoint of lower HFP production costs. Note that the post-contact mixture may be substantially free of the media. "Substantially free" means that the content of the media in the total post-contact mixture is 1 mol% or less. When the post-contact mixture is substantially free of the media, the HFP production efficiency is high and the burden of separation operations is reduced.

[0025] Furthermore, in the contact between compound (A), compound (B), and nitrogen, the order of contact is not particularly limited. Compound (A), compound (B), and nitrogen may be contacted simultaneously, or a mixture of compound (A) and nitrogen may be contacted with compound (B). Similarly, in the contact between compound (A), TFE, compound (B), and nitrogen, the order of contact is not particularly limited. Compound (A), TFE, compound (B), and nitrogen may be contacted simultaneously, or a mixture of compound (A) and nitrogen may be contacted with TFE and compound (B), or a mixture of compound (A) and TFE may be contacted with compound (B) and nitrogen, or a mixture of compound (A) and TFE may be contacted with nitrogen before contacting compound (B).

[0026] The ratio of nitrogen to the total amount of compound (A), compound (B), and TFE and nitrogen as needed, can be, for example, 0 to 75 mol%. The ratio of nitrogen is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 20 mol% or less. When the ratio of nitrogen is below the upper limit, a large amount of HFP is produced in the reaction process, and the separation operation after the reaction is made easier. The ratio of nitrogen may also be 0 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more. When the ratio of nitrogen is above the lower limit, the HFP concentration inside the reactor is low, which has the advantage of suppressing the generation of sequential reaction by-products derived from HFP, and also has the advantage of suppressing the formation of hot spots associated with the reaction because the raw material concentration is low.

[0027] Furthermore, the total content of the medium relative to the total amount of compound (A), compound (B), and TFE and medium as needed in the mixture after contact is not particularly limited, and for example, it can be 0 to 75 mol%. The total content of the medium is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 20 mol% or less. When the total content of the medium is below the upper limit, a large amount of HFP is produced in the reaction process, and the separation operation after the reaction is made easier. Also, the total content of the medium may be 0 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more. When the total content of the medium is above the lower limit, the HFP concentration inside the reactor is low, which has the advantage of suppressing the generation of sequential reaction by-products derived from HFP, and also has the advantage of suppressing the formation of hot spots associated with the reaction because the raw material concentration is low.

[0028] [Process] The manufacturing method of this embodiment may have other steps besides the contact step, supply step, and reaction step. Other steps include, for example, a first preheating step in which compound (A) is preheated to a first preheating temperature of less than 780°C before contact with compound (B); a second preheating step before the contact step in which compound (A) that has gone through the first preheating step is mixed with a second preheating heat medium heated at a second preheating heat medium heating temperature that is higher than the first preheating temperature but less than 780°C to obtain a second post-preheated mixture; a compound (B) preheating step before contact with compound (A) and compound (B) in which compound (B) is preheated to a compound (B) preheating temperature of less than 780°C; and a TF used as necessary before contact with compound (A) and compound (B). Examples of the steps include: a TFE preheating step in which E is preheated to a TFE preheating temperature of less than 780°C; a contact preheating step in which compound (A) and compound (B) are brought into contact with a contact heat transfer medium heated to a heating temperature higher than the temperature of compound (A) at the time of contact but less than 780°C; a mixture preheating step in which the post-contact mixture is preheated to a mixture preheating temperature of less than 780°C after the contact step and before the supply step; a discharge step in which the post-reaction composition containing the product obtained in the reaction step is discharged from the reactor; and a washing step in which the post-reaction composition discharged in the discharge step is washed.

[0029] From the viewpoint of improving the selectivity of HFP, the manufacturing method of this embodiment preferably further includes at least one of the first preheating step and the mixture preheating step. In other words, in the manufacturing method of this embodiment, it is preferable to preheat compound (A) at the first preheating temperature and then bring it into contact with compound (B), or to bring it into contact with compound (B) and then preheat it at the mixture preheating temperature before supplying it to the reactor.

[0030] If the manufacturing method of this embodiment further includes the first preheating step, it is preferable that the manufacturing method of this embodiment further includes the second preheating step from the viewpoint of improving the selectivity of HFP. Here, "second preheating heat transfer medium" is the heat transfer medium used in the second preheating step, and "second preheating heat transfer medium heating temperature" is the heating temperature of the second preheating heat transfer medium. Hereinafter, the mixture obtained by the second preheating step will also be called the "mixture after second preheating." In other words, in the manufacturing method of this embodiment, it is preferable to contact compound (B) with a mixture of compound (A) preheated at the first preheating temperature and compound (B) as a second preheated mixture obtained by mixing compound (A) preheated at the first preheating temperature with the second preheating heat transfer medium heated at the second preheating heat transfer medium heating temperature. The manufacturing method of this embodiment may have a contact preheating step in which compound (A) and compound (B) are brought into contact with a contact heat transfer medium heated at a heating temperature higher than the temperature of compound (A) at the time of contact and less than 780°C.

[0031] Here, the "post-contact mixture" is, as described above, a mixture obtained by contact between compound (A) and compound (B). The post-contact mixture includes at least compound (A) and compound (B). If the manufacturing method of this embodiment further includes a second preheating step, the post-contact mixture includes compound (A), the second preheating heat transfer medium, and compound (B). On the other hand, if the manufacturing method of this embodiment further includes a preheating step during contact, the post-contact mixture includes compound (A), compound (B), and the heat transfer medium for contact. The post-contact mixture may be the result of a reaction between some of the thermal decomposition products of compound (A), or it may be the result of a reaction between some of the thermal decomposition products of compound (A) and some of the thermal decomposition products of compound (B).

[0032] From the viewpoint of improving the selectivity of HFP, the manufacturing method of this embodiment further includes the compound (B) preheating step, and it is preferable to bring compound (A) into contact with compound (B) after the compound (B) preheating step in the contact step. In other words, in the manufacturing method of this embodiment, it is preferable to preheat compound (B) to the compound (B) preheating temperature before bringing it into contact with compound (A). Note that compound (A) brought into contact with compound (B) after the compound (B) preheating step may or may not be preheated.

[0033] Next, the details of each step in the manufacturing method of the present embodiment will be described.

[0034] <Preheating step of compound (A)> (First preheating step) As described above, the manufacturing method of the present embodiment preferably further includes the first preheating step. In the first preheating step, compound (A) is preheated at the first preheating temperature. The first preheating temperature is less than 780°C and may be any temperature higher than the temperature of compound (A) before preheating. For example, it may be 50°C or higher and less than 780°C. From the perspective of improving the selectivity of HFP, the first preheating temperature is preferably 100°C or higher, more preferably 250°C or higher, further preferably 400°C or higher, particularly preferably 500°C or higher, and extremely preferably 600°C or higher. The first preheating temperature may be 750°C or lower, or 700°C or lower.

[0035] In the first preheating step, the preheating of compound (A) may be performed by supplying compound (A) to a preheater heated to the first preheating temperature, or may be performed by heating the preheater to the first preheating temperature after supplying compound (A) to the preheater. Also, as described later, the preheating of compound (A) in the first preheating step may be performed by mixing with a heat medium. Further, as described later, compound (A) and a diluting medium may be mixed in advance before passing through the first preheating step, and a mixture of compound (A) and the diluting medium (hereinafter also referred to as "post-dilution mixture") may be preheated at the first preheating temperature. That is, the first preheating step may be a step of preheating compound (A) contained in the post-dilution mixture at the first preheating temperature. In the first preheating step, when the preheating of compound (A) is performed by heating the preheater, the first preheating temperature is the set temperature in heating, that is, the heating temperature of the preheater. The preheater is not particularly limited, and a preheater having the same specifications as the reactor described later may be used. Note that the preheater and the reactor used in the manufacturing method of the present embodiment may have the same specifications or different specifications.

[0036] (Second Preheating Step) As described above, when the manufacturing method of the present embodiment includes the first preheating step, it preferably further includes the second preheating step. In the second preheating step, a mixture after the second preheating is obtained by mixing the compound (A) that has undergone the first preheating step and the second preheating heat medium heated at a second preheating heat medium heating temperature higher than the first preheating temperature. In the present disclosure, the "heat medium" means a medium that does not substantially decompose alone at the reaction temperature, and specifically, it is preferably a medium that does not substantially decompose alone at a temperature of 1100°C or lower. Examples of the second preheating heat medium include inert gases such as nitrogen gas, helium gas, and argon gas, and nitrogen gas is preferred from the viewpoint of easy availability. The second preheating heat medium is preferably a gas at the second preheating heat medium heating temperature.

[0037] The second preheating heat medium heating temperature is higher than the first preheating temperature, and examples include exceeding 100°C and being 1100°C or lower. From the viewpoint of suppressing the generation of by-products, the second preheating heat medium heating temperature is preferably higher than 350°C, more preferably higher than 450°C, further preferably 500°C or higher, particularly preferably 850°C or higher, extremely preferably 900°C or higher, and most preferably 1000°C or higher. Also, from the viewpoint of suppressing the generation of by-products, the second preheating heat medium heating temperature is preferably 1100°C or lower, more preferably 1050°C or lower, and further preferably 1000°C or lower. In another aspect, from the viewpoints of suppressing the generation of by-products and operability, the second preheating heat medium heating temperature is preferably 700 to 1100°C, and more preferably 800 to 1000°C. The second preheating heat medium heating temperature is preferably 10°C or higher, more preferably 50°C or higher, further preferably 200°C or higher, and particularly preferably 925°C or higher than the first preheating temperature. The heating of the second preheating heat medium is performed, for example, by supplying the second preheating heat medium to a heat medium heater and heating it at the second preheating heat medium heating temperature. The mixing of the compound (A) and the second preheating heat medium may be performed using a mixer, or may be performed by merging the flow path through which the compound (A) passes and the flow path through which the second preheating heat medium passes.

[0038] The amount of the second preheating heat transfer medium added is, for example, 0 to 75 mol% of the total amount of compound (A), compound (B), and the second preheating heat transfer medium preheated at the first preheating temperature. The amount of the second preheating heat transfer medium added to the total amount of compound (A), compound (B), and the second preheating heat transfer medium is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 20 mol% or less. By keeping the amount of the second preheating heat transfer medium added below the above upper limit, a large amount of HFP is produced in the reaction step, and the separation operation after the reaction is facilitated. Furthermore, the amount of the second preheating heat transfer medium added to the total amount of compound (A), compound (B), and the second preheating heat transfer medium may be 0 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more. When the amount of the second preheating heat transfer medium added is equal to or greater than the lower limit, the temperature of compound (A) rises rapidly and the selectivity of HFP improves.

[0039] The content of the second preheating heat transfer medium relative to the total amount of compound (A) and the second preheating heat transfer medium in the mixture after the second preheating before contact with compound (B) can be, for example, 0 to 82.5 mol%. The content of the second preheating heat transfer medium relative to the total amount of compound (A) and the second preheating heat transfer medium is preferably 55.5 mol% or less, more preferably 44.4 mol% or less, and even more preferably 33.3 mol% or less. When the content of the second preheating heat transfer medium is below the above upper limit, the amount of HFP produced in the reaction step is large, and the separation operation after the reaction is made easier. Furthermore, the content of the second preheating heat transfer medium relative to the total amount of compound (A) and the second preheating heat transfer medium may be 0 mol% or more, preferably 5.5 mol% or more, and more preferably 11.1 mol% or more. When the content of the second preheating heat transfer medium is above the above lower limit, the temperature of compound (A) rises quickly and the selectivity of HFP is improved.

[0040] (First preheating step using a heat medium) As described above, the preheating of compound (A) in the first preheating step may be carried out by mixing compound (A) with a heat medium. Hereinafter, the heat medium used in the first preheating step is also referred to as "heat medium for first preheating". In the first preheating step using a heat medium, for example, the heat medium for first preheating heated to the heat medium heating temperature for first preheating in a heat medium heater and compound (A) are mixed to obtain a mixture after first preheating, whereby compound (A) contained in the mixture after first preheating is preheated to the first preheating temperature. The first preheating temperature in the first preheating step using a heat medium, that is, the set temperature in heating, is the temperature T of compound (A) before mixing １ (K), the heat medium heating temperature T for first preheating ２ (K), the flow rate M of compound (A) to be mixed １ (kg / h), and the flow rate M of the heat medium for first preheating to be mixed ２ (kg / h), the average specific heat C of compound (A) １ (kcal / kg·K), the specific heat C of the heat medium for first preheating ２ (kcal / kg·K), the temperature T of the mixture after first preheating theoretically estimated from the following formula based on the temperature T of compound (A) before mixing ３ (K). Formula: (T ３ - T １ ) × M １ × C １ = (T ２ - T ３ ) × M ２ × C ２

[0041] The types of the heat medium for first preheating include the same ones as those of the heat medium for second preheating. When both the heat medium for first preheating and the heat medium for second preheating are used in the preheating step, they may be of the same type or different types from each other. From the viewpoint of facilitating the separation operation after the reaction, it is preferable that they are of the same type. The heat medium heating temperature for first preheating is the temperature T of the mixture after first preheating ３Any temperature that can reach the first preheating temperature for the purpose of this is acceptable, for example, a temperature between 100°C and 1100°C. The heating temperature of the first preheating heat medium is above 100°C, and from the viewpoint of suppressing the generation of by-products, it is preferably above 350°C, more preferably above 450°C, even more preferably above 500°C, particularly preferably above 850°C, extremely preferably above 900°C, and most preferably above 1000°C. Furthermore, from the viewpoint of suppressing the generation of by-products, the heating temperature of the first preheating heat medium is preferably 1100°C or lower, more preferably below 1050°C, and even more preferably below 1000°C.

[0042] The mixing of compound (A) and the first preheating heat transfer medium may be performed using a mixer, or by merging the channel through which compound (A) passes and the channel through which the first preheating heat transfer medium passes. The content of the first preheating heat transfer medium in the mixture after the first preheating before contact with compound (B) is determined by the temperature T of the mixture after the first preheating. ３ The amount is not particularly limited as long as it results in the desired first preheating temperature. The content of the first preheating heat transfer medium in the mixture after the first preheating can be, for example, 82.5 mol% or less relative to the total of compound (A) and the first preheating heat transfer medium. The content of the first preheating heat transfer medium relative to the total of compound (A) and the first preheating heat transfer medium is preferably 55.5 mol% or less, more preferably 44.4 mol% or less, and even more preferably 33.3 mol% or less. Furthermore, the content of the first preheating heat transfer medium relative to the total of compound (A) and the first preheating heat transfer medium may be 0 mol% or more, preferably 5.5 mol% or more, and more preferably 11.1 mol% or more.

[0043] Furthermore, when a first preheating heat transfer medium is used in the first preheating step, in the second preheating step, a second preheating mixture containing compound (A), the first preheating heat transfer medium, and the second preheating heat transfer medium is obtained by mixing the first preheated mixture, which is a mixture of compound (A) and the first preheating heat transfer medium, with the second preheating heat transfer medium.

[0044] (Mixing of compound (A) and diluent) As described above, compound (A) and the diluent may be mixed in advance before the first preheating step. In this disclosure, "diluent" means a medium that does not substantially decompose on its own at the temperature at which it is mixed with compound (A). It is desirable that the diluent, like the heat medium, is a medium that does not substantially decompose on its own at the reaction temperature, and more specifically, a medium that does not substantially decompose on its own at temperatures of 1100°C or lower. The type of diluent can be the same as that of the second preheating heat medium. When at least one of the first preheating heat medium and the second preheating heat medium is used in the preheating step, the diluent and at least one of the first preheating heat medium and the second preheating heat medium may be the same type of medium or different types of medium, but it is preferable that they be the same type of medium from the viewpoint of facilitating separation after the reaction. The temperature of the diluent when mixed with compound (A) is not particularly limited, and for example, a temperature lower than the first preheating temperature can be mentioned.

[0045] The mixing of compound (A) and the diluent may be performed using a mixer, or by merging the channel through which compound (A) passes and the channel through which the diluent passes. The content of the diluent relative to the total of compound (A) and the diluent is not particularly limited. An example of the diluent content is 82.5 mol% or less relative to the total of compound (A) and the diluent. Preferably, the content of the diluent relative to the total of compound (A) and the diluent is 55.5 mol% or less, more preferably 44.4 mol% or less, and even more preferably 33.3 mol% or less. Furthermore, the content of the diluent relative to the total of compound (A) and the diluent may be 0 mol% or more, preferably 5.5 mol% or more, and more preferably 11.1 mol% or more. By keeping the content of the diluent relative to the total of compound (A) and the diluent below the above upper limit, a large amount of HFP is produced in the reaction step, and the separation operation after the reaction becomes easier. On the other hand, by ensuring that the content of the diluent relative to the total of compound (A) and the diluent is above the above lower limit, the HFP concentration inside the reactor is reduced. This has the advantage of suppressing the generation of sequential reaction by-products derived from HFP, and also suppressing the formation of hot spots associated with the reaction due to the lower concentration of the starting materials.

[0046] Furthermore, if compound (A) and the diluent are mixed in advance before the first preheating step, and the second preheating step is then performed, the mixture after the second preheating step includes compound (A), the diluent, and the heat transfer medium for the second preheating step.

[0047] <Preheating step of compound (B)> As described above, the manufacturing method of this embodiment preferably further includes a compound (B) preheating step in which compound (B) is heated before contact with compound (A), from the viewpoint of improving the selectivity of HFP. When C318 is used as compound (B), the compound (B) preheating temperature in the compound (B) preheating step can be, for example, 100 to 350°C, and from the viewpoint of improving the selectivity of HFP, 150 to 300°C is preferred. When R125 is used as compound (B), the compound (B) preheating temperature in the compound (B) preheating step can be, for example, 100 to 750°C, and from the viewpoint of improving the selectivity of HFP, 400 to 700°C is preferred, and 600 to 700°C is more preferred. Preheating of compound (B) is performed, for example, by supplying compound (B) to a compound (B) preheater for preheating compound (B) and heating it at the compound (B) preheating temperature. The compound (B) preheater is not particularly limited, and one with the same specifications as the reactor described later may be used. The preheater and reactor used in the manufacturing method of this embodiment may have the same specifications or different specifications.

[0048] <TFE Preheating Step> In the manufacturing method of this embodiment, if the mixture after contact contains TFE, the method may further include a TFE preheating step in which the TFE is preheated to a TFE preheating temperature of less than 780°C before contact with compound (A) and compound (B). Examples of TFE preheating temperatures include 50 to 250°C, and from the viewpoint of TFE stability, 50 to 200°C is preferred, and 100 to 150°C is more preferred. Preheating of the TFE is performed, for example, by supplying the TFE to a TFE preheater for preheating TFE and preheating it at the above TFE preheating temperature. A TFE preheater with the same specifications as the reactor described later is used.

[0049] <Preheating step at contact> In the manufacturing method of this embodiment, preheating of compound (A) and compound (B) may be performed simultaneously with the contact step described later. Specifically, the manufacturing method of this embodiment may further include a preheating step at contact, in which compound (A), a heat transfer medium for contact heated to a heating temperature higher than the temperature of compound (A) at the time of contact but less than 780°C, and compound (B) are brought into contact. By going through the preheating step at contact, a preheated post-contact mixture is obtained. The type of heat transfer medium for contact is the same as that for the second preheating heat transfer medium. When at least one selected from the group consisting of the first preheating heat transfer medium, diluent, and second preheating heat transfer medium is used before the preheating step at contact, the heat transfer medium for contact may be the same type as at least one selected from the group consisting of the first preheating heat transfer medium, diluent, and second preheating heat transfer medium, or a different type of medium may be used, but it is preferable to use the same type of medium from the viewpoint of facilitating separation operations after the reaction.

[0050] The heating temperature of the heat transfer medium for contact is higher than the temperature of compound (A) when it comes into contact with compound (B), for example, between 100°C and 1100°C. From the viewpoint of suppressing the generation of by-products, the heating temperature of the heat transfer medium for contact is preferably above 350°C, more preferably above 450°C, even more preferably above 500°C, particularly preferably above 850°C, extremely preferably above 900°C, and most preferably above 1000°C. Furthermore, from the viewpoint of suppressing the generation of by-products, the heating temperature of the heat transfer medium for contact is preferably 1100°C or lower, more preferably below 1050°C, and even more preferably below 1000°C. In another embodiment, from the viewpoint of suppressing the generation of by-products and ease of operation, the heating temperature of the heat transfer medium for contact is preferably between 700°C and 1100°C, and more preferably between 800°C and 1000°C. The heating temperature of the contact heat transfer medium is more preferably 50°C or more higher than the temperature of compound (A) when it comes into contact with compound (B), more preferably 100°C or more higher, even more preferably 200°C or more higher, and particularly preferably 300°C or more higher. The heating of the contact heat transfer medium is performed, for example, by supplying the contact heat transfer medium to a heat transfer medium heater and heating it to the above-mentioned heating temperature of the contact heat transfer medium. Contact between compound (A), the contact heat transfer medium, and compound (B) may be performed using a mixer, or by merging the flow path for compound (A), the flow path for the contact heat transfer medium, and the flow path for compound (B) at a single point.

[0051] The amount of heat transfer medium added to the contact medium is, for example, 0 to 75 mol% of the total amount of compound (A), compound (B), and heat transfer medium. The amount of heat transfer medium added to the total amount of compound (A), compound (B), and heat transfer medium is preferably 50 mol% or less, more preferably 40 mol% or less, even more preferably 30 mol% or less, and particularly preferably 20 mol% or less. When the amount of heat transfer medium added is below the above upper limit, the amount of HFP produced in the reaction step is large, and the separation operation after the reaction is easy. Furthermore, the amount of heat transfer medium added to the total amount of compound (A), compound (B), and heat transfer medium may be 0 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, and even more preferably 20 mol% or more. When the amount of heat transfer medium added is above the above lower limit, the temperature of compound (A) rises quickly, and the selectivity of HFP is improved.

[0052] <Mixture Preheating Step> The manufacturing method of this embodiment may further include a mixture preheating step, which preheats the post-contact mixture to a mixture preheating temperature of less than 780°C, after the contact step described later and before the supply step described later. The post-contact mixture to be preheated in the mixture preheating step includes at least compound (A) and compound (B) as described above, and may include a medium, TFE, or other components. The post-contact mixture to be preheated in the mixture preheating step may have undergone other preheating steps, or may not have undergone any preheating steps.

[0053] The preheating temperature of the mixture is less than 780°C and should be higher than the temperature of the mixture after contact before preheating, for example, between 50°C and 780°C. From the viewpoint of improving the selectivity of HFP, the preheating temperature of the mixture is preferably 100°C or higher, more preferably 250°C or higher, even more preferably 400°C or higher, particularly preferably 500°C or higher, and very preferably 600°C or higher. The preheating temperature of the mixture may be 750°C or lower, or 700°C or lower.

[0054] In the mixture preheating step, the mixture may be supplied after contact with a preheater heated to the mixture preheating temperature, or the mixture may be supplied after contact with the preheater, and then the preheater may be heated to the mixture preheating temperature. The preheater is not particularly limited, and one with the same specifications as the reactor described later may be used. The preheater and reactor used in the manufacturing method of this embodiment may have the same specifications or may have different specifications.

[0055] <Contacting Step> In the contacting step, compound (A) and compound (B) are brought into contact to obtain a post-contact mixture. The contacting step may be performed before or after the supplying step, which will be described later. In other words, the contact between compound (A) and compound (B) may be performed outside the reactor before supplying them to the reactor, or it may be performed inside the reactor after they have been supplied to the reactor separately. In the manufacturing method of this embodiment, the post-contact mixture may be obtained either inside or outside the reactor. The reaction between compound (A) and compound (B) mainly proceeds in the reaction step, which will be described later, but it may proceed partially before the post-contact mixture is formed, and if the contacting step is performed before the supplying step, it may proceed partially between the time the post-contact mixture is formed and before it is supplied to the reactor.

[0056] In the contact step, compound (A) that has undergone the first preheating step and the second preheating step may be brought into contact with compound (B) that has undergone the compound (B) preheating step, or compound (A) that has undergone the first preheating step but not the second preheating step may be brought into contact with compound (B) that has undergone the compound (B) preheating step. When compound (A) that has undergone the first preheating step and the second preheating step is brought into contact with compound (B), the aforementioned mixture after the second preheating step is brought into contact with compound (B). Also, when preheating of compound (A) in the first preheating step is performed by mixing compound (A) with the first preheating heat transfer medium, when compound (A) that has undergone the first preheating step but not the second preheating step is brought into contact with compound (B), the aforementioned mixture after the first preheating step is brought into contact with compound (B). Furthermore, in the contact step, compound (A), compound (B), and the contact heat transfer medium may be brought into contact simultaneously, thereby performing the contact step and the preheating step at contact simultaneously.

[0057] Furthermore, in the contact step, at least one of compound (A) and compound (B) may be in contact without undergoing a preheating step. In that case, it is preferable to go through a mixture preheating step after the contact step. For example, one configuration is to simultaneously bring compound (A), compound (B), and the diluent, neither of which has undergone a preheating step, into contact, and then go through a mixture preheating step. If the post-contact mixture contains TFE, in the contact step, compound (A), compound (B), and TFE may be brought into contact simultaneously, or a mixture of compound (A) and TFE may be brought into contact with compound (B), or a mixture of compound (A), compound (B), and TFE may be brought into contact. Alternatively, after bringing compound (A) and compound (B) into contact in the contact step, the resulting post-contact mixture may be mixed with TFE.

[0058] <Supplying Process> In the supplying process, compound (A) and compound (B) are supplied into the reactor. In the manufacturing method of this embodiment, compound (A) and compound (B) may be supplied separately into the reactor and then brought into contact within the reactor, or a mixture obtained by bringing compound (A) and compound (B) into contact may be supplied into the reactor. In other words, in the manufacturing method of this embodiment, the supplying process may be followed by the contacting process, or the contacting process may be followed by the supplying process.

[0059] The reactor only needs to be able to withstand the temperature and pressure described later, and its shape and structure are not particularly limited. Examples of reactors include tubular reactors. Examples of reactor materials include acid-resistant metal materials such as copper, stainless steel, Hastelloy, and Inconel. The reactor may be equipped with heating means such as an electric heater to heat the inside of the reactor. The reactor may be preheated to the reaction temperature before supplying compound (A) and compound (B), or it may be heated to the reaction temperature after supplying compound (A) and compound (B). Compound (A) and compound (B) may be supplied into the reactor through a supply channel. The supply channel only needs to be a flow path through which compound (A) and compound (B), and any media and TFE used as needed, can pass, and its shape and size are not particularly limited. Examples of supply channel materials include the same materials as those used for the reactor.

[0060] Furthermore, from the viewpoint of suppressing the generation of by-products, it is desirable to use a reactor with a mixing mechanism. Examples of reactors with a mixing mechanism include ejector-type reactors and reactors with mixers. By using a reactor with a mixing mechanism, when compound (A), compound (B), and TFE and medium used as needed are supplied to the reactor, they become nearly homogeneous instantaneously, suppressing the generation of by-products.

[0061] The reactor may or may not be filled with a catalyst. Filling the reactor with a catalyst means filling and holding a catalyst-containing substance in the space inside the reactor. One example of a form in which the reactor is filled with a catalyst-containing substance is used to fill the space inside the reactor and block the flow path, and the post-contact mixture is passed through the gaps in the catalyst-containing substance to efficiently bring the post-contact mixture into contact with the catalyst. The catalyst-containing substance can be the catalyst itself, or a catalyst-supported body in which the catalyst is supported on a carrier. Examples of catalysts include cobalt(II) fluoride and cesium fluoride. From the viewpoint of manufacturing stability, it is preferable that the reactor is not filled with a catalyst. By not using a catalyst, there is no concern that the catalyst will be deactivated even if the reactor is heated to a high temperature, and catalyst costs, catalyst replacement work, and catalyst holding materials are eliminated.

[0062] <Reaction Process> In the reaction process, as described above, compounds (A) and (B) supplied into the reactor in the supply process are heated to a reaction temperature of 780°C or higher. In other words, in the reaction process, the post-contact mixture in the reactor is heated to a reaction temperature of 780°C or higher.

[0063] Examples of reaction temperatures include 780 to 1000°C. A reaction temperature of 800°C or higher is preferred, 830°C or higher is more preferred, and 850°C or higher is even more preferred. Furthermore, a reaction temperature of 1000°C or lower is preferred, 950°C or lower is more preferred, 900°C or lower is even more preferred, 870°C or lower is particularly preferred, and 850°C or lower is extremely preferred. A reaction temperature above the lower limit suppresses the formation of by-products and increases the selectivity of HFP. Similarly, a reaction temperature below the upper limit suppresses the formation of by-products and increases the selectivity of HFP. "Reaction temperature" refers to the set temperature during heating, i.e., the heating temperature of the reactor. In this embodiment, this also includes cases where at least a portion of compound (A) and compound (B) in the reactor has not reached the reaction temperature. It is presumed that the formation of by-products in the reaction process is likely to occur near the inner surface of the reactor, which is susceptible to the effects of heating. Therefore, the amount of by-products produced is thought to correlate more strongly with the reactor heating temperature than with the temperature of compound (A) in the center of the reactor.

[0064] In the reaction step, the time for heating compound (A) and compound (B) in the reactor at the reaction temperature is preferably 2 seconds or less. In other words, in the reaction step, the time for heating the contact mixture in the reactor at the reaction temperature is preferably 2 seconds or less. Hereinafter, the time for heating the contact mixture in the reactor at the reaction temperature is also referred to as the "reaction time". When the reaction method in the reaction step is continuous and the reactor is continuously heated at the reaction temperature, the above reaction time is the residence time from when compound (A) and compound (B) are supplied to the reactor until the product is discharged. The residence time is calculated, for example, from the reactor volume, supply flow rate, outlet flow rate, average reactor temperature, and reactor pressure. The above reaction time can be, for example, 0.01 to 2 seconds. The above reaction time is preferably 0.1 seconds or more, more preferably 0.2 seconds or more, even more preferably 0.3 seconds or more, and particularly preferably 0.34 seconds or more. Furthermore, the above reaction time is preferably 2 seconds or less, more preferably 1 second or less, and even more preferably 0.5 seconds or less. If the reaction time is below the upper limit, the generation of by-products is suppressed. If the reaction time is above the lower limit, the energy efficiency is high, the conversion rate of the reaction is high, and the amount of HFP produced is increased.

[0065] In the reaction process, the gauge pressure inside the reactor can be, for example, 0 kPaG or more and less than 200 kPaG. The gauge pressure inside the reactor is preferably 1 kPaG or more, more preferably 3 kPaG or more, and even more preferably 5 kPaG or more. Furthermore, the gauge pressure inside the reactor is preferably 190 kPaG or less, more preferably 150 kPaG or less, even more preferably 100 kPaG or less, particularly preferably 50 kPaG or less, and extremely preferably 10 kPaG or less. In another embodiment, the gauge pressure inside the reactor is preferably 1 to 190 kPaG, more preferably 3 to 150 kPaG, even more preferably 5 to 100 kPaG, and particularly preferably 50 to 100 kPaG. By keeping the gauge pressure inside the reactor below the above upper limits, the generation of by-products is suppressed and the pressure inside the reactor can be easily adjusted. When the gauge pressure inside the reactor is above the lower limit mentioned above, the reaction efficiency per unit volume is high, resulting in a larger amount of HFP being produced.

[0066] The post-reaction composition obtained through the reaction step contains at least the product obtained by the reaction of compound (A) and compound (B), and may further contain unreacted raw materials, compound (A) and compound (B). Furthermore, if a medium is used in a step prior to the reaction step, the post-reaction composition may further contain the said medium. Furthermore, if the post-contact mixture contains TFE, the post-reaction composition may further contain unreacted TFE. Hereinafter, a post-reaction composition obtained without using a medium, or a composition obtained by removing the medium from a post-reaction composition obtained with a medium, will also be referred to as a "specific composition."

[0067] In the reaction step, the product obtained by the reaction of compound (A) and compound (B) contains at least HFP, and may also contain compounds other than HFP. Examples of compounds other than HFP include the starting materials compound (A) and compound (B), as well as TFE, a reaction intermediate, and by-products such as perfluoroisobutylene, pentafluoroethane, hexafluoroethane, and R1225ye, which are used as needed. In other words, the specific composition contains at least HFP, and may also contain the HFP and the unreacted starting materials compound (A) and compound (B), and TFE, which is used as needed, and may further contain by-products. The HFP content in the total specific composition is, for example, 0.5 mol% or more, preferably 1.0 mol% or more, more preferably 2.0 mol% or more, even more preferably 5.0 mol% or more, particularly preferably 10.0 mol% or more, and very preferably 15.0 mol% or more.

[0068] The HFP production efficiency, that is, the ratio of the amount of HFP produced to the total amount of raw materials consumed, is, for example, 0.05 or more, preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.4 or more, and particularly preferably 0.7 or more. Here, the raw materials in this embodiment are compound (A) and compound (B), and TFE used as needed. The HFP production efficiency is calculated by considering the flow rates of compound (A), TFE, and compound (B) among the raw materials supplied from the reactor supply port as X mol / h, and the flow rates of compound (B) as Z mol / h among the components discharged from the reactor outlet as X' mol / h, TFE, and compound (B) as Y' mol / h, and the flow rates of HFP as A mol / h, with compound (B) having C Ｂ When X ≥ X', Y ≥ Y', and Z ≥ Z', the efficiency can be calculated using the following formula: Formula: Production efficiency = 3 × A / (1 × (X - X') + 2 × (Y - Y') + C Ｂ × (Z - Z')) The proportion of each component in the post-reaction composition can be determined, for example, by gas chromatography analysis.

[0069] The HFP generation efficiency can be calculated using the following formula (1) if X ≥ X', Y < Y', and Z ≥ Z', and using the following formula (2) if X ≥ X', Y ≥ Y', and Z < Z'. Formula (1): Generation efficiency = 3 × A / (1 × (X - X') + C Ｂ × (Z - Z')) Equation (2): Production efficiency = 3 × A / (1 × (X - X') + 2 × (Y - Y'))

[0070] The specific composition may contain R1225ye as a by-product. However, R1225ye has a boiling point close to that of the target product, HFP, making it difficult to separate from HFP. Therefore, it is preferable that the R1225ye content in the specific composition be low. The R1225ye content relative to the entire specific composition can be, for example, 0.3 mol% or less, preferably 0.15 mol% or less, and more preferably 0.05 mol% or less.

[0071] When a specific composition contains R1225ye, the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the specific composition (moles of HFP / molar amount of R1225ye) is preferably 50.000 or more, more preferably 60.000 or more, even more preferably 80.000 or more, and particularly preferably 90.000 or more, in terms of the large amount of HFP produced as a by-product.

[0072] <Other Processes> In the discharge process, the post-reaction composition, including the product obtained in the reaction process, is discharged from the reactor. As described above, the post-reaction composition may include the unreacted raw materials, compound (A) and compound (B), and TFE, which may be used as needed. The medium contained in the post-contact mixture is also contained in the post-reaction composition. In the washing process, the post-reaction composition discharged in the discharge process is washed. Specifically, for example, water is passed through the post-reaction composition to remove the acid generated by the reaction.

[0073] <Manufacturing Apparatus> Next, an example of a manufacturing apparatus used in the manufacturing method of this embodiment will be described with reference to Figures 1 to 5. The manufacturing apparatus shown in Figure 1 is used in the manufacturing method described above, in which compound (A) is preheated in the first preheating step by heating a preheater, and the second preheated mixture obtained by mixing compound (A) with the second preheating heat transfer medium in the second preheating step and compound (B) preheated in the compound (B) preheating step are supplied separately to the reactor. Note that the manufacturing apparatus shown in Figure 1 may also be used in a manufacturing method in which compound (A), preheated by heating a preheater in the first preheating step, is supplied directly to the reactor without going through the second preheating step.

[0074] The manufacturing apparatus 100 shown in Figure 1 comprises a compound (A) container 1 for containing compound (A) before preheating, a compound (A) preheater 4 for preheating compound (A) in the first preheating step, a heat transfer medium container 5 for containing a second preheating heat transfer medium before heating, a heat transfer medium heater 8 for heating the second preheating heat transfer medium, a compound (B) container 9 for containing compound (B) before preheating, a compound (B) preheater 12 for preheating compound (B), and a reactor 13 for heating compound (A) and compound (B) at the reaction temperature in the reaction step. A compound (A) supply passage 2 is provided between the compound (A) container 1 and the compound (A) preheater 4 to supply compound (A) from the compound (A) container 1 to the compound (A) preheater 4. Similarly, a heat transfer medium supply passage 6 is provided between the heat transfer medium container 5 and the heat transfer medium heater 8 to supply the second preheating heat transfer medium from the heat transfer medium container 5 to the heat transfer medium heater 8. Similarly, a compound (B) supply passage 10 is provided between the compound (B) container 9 and the compound (B) preheater 12 to supply compound (B) from the compound (B) container 9 to the compound (B) preheater 12. Compound (A) supply passage 2, heat transfer medium supply passage 6, and compound (B) supply passage 10 are each provided with a compound (A) flow rate control device 3 for controlling the flow rate of compound (A), a heat transfer medium flow rate control device 7 for controlling the flow rate of the second preheating heat transfer medium, and a compound (B) flow rate control device 11 for controlling the flow rate of compound (B).

[0075] On the other hand, between the compound (A) preheater 4 and the reactor 13, compound (A) supply channels 18 and 23 are provided to supply compound (A) from the compound (A) preheater 4 to the reactor 13. At a confluence point 20 located between the compound (A) preheater 4 and the reactor 13, compound (A) supply channels 18 and 23 merge with a heat transfer medium supply channel 19 that supplies a second preheating heat transfer medium from the heat transfer medium heater 8 to the confluence point 20. Between the compound (B) preheater 12 and the reactor 13, compound (B) supply channel 21 is provided to supply compound (B) from the compound (B) preheater 12 to a separate supply port in the reactor 13 from compound (A). Furthermore, in the manufacturing apparatus 100 shown in Figure 1, on the opposite side of the compound (A) supply passage 23 in the reactor 13, a washing tower 15 for washing the post-reaction composition, a recovery unit 16 for recovering the washed post-reaction composition, and an analytical device 17 for analyzing the components of the post-reaction composition are provided via a discharge passage 14.

[0076] Next, an example of the manufacturing method of this embodiment using the manufacturing apparatus 100 shown in Figure 1 will be described. Compound (A), contained in the compound (A) container 1, is supplied via the compound (A) supply passage 2 to the compound (A) preheater 4, which is heated to the first preheating temperature. Here, the flow rate of compound (A) is controlled by the compound (A) flow rate control device 3. On the other hand, the second preheating heat transfer medium, contained in the heat transfer medium container 5, is supplied via the heat transfer medium supply passage 6 to the heat transfer medium heater 8, which is heated to the second preheating heat transfer medium heating temperature. The flow rate of the second preheating heat transfer medium is controlled by the heat transfer medium flow rate control device 7, similar to compound (A). Similarly, compound (B), contained in the compound (B) container 9, is supplied via the compound (B) supply passage 10 to the compound (B) preheater 12, which is preheated to the compound (B) preheating temperature. The flow rate of compound (B) is controlled by the compound (B) flow rate control device 11, similar to compound (A) and the second preheating heat transfer medium.

[0077] Next, compound (A), preheated at the first preheating temperature in compound (A) preheater 4, and the second preheating heat medium, heated at the second preheating heat medium heating temperature in heat medium heater 8, are mixed at the confluence point 20 via compound (A) supply channel 18 and heat medium supply channel 19, respectively, to form the second post-preheated mixture. The second post-preheated mixture obtained at the confluence point 20 is further supplied to the reactor 13, which is heated to the reaction temperature, via compound (A) supply channel 23. Meanwhile, compound (B), preheated at compound (B) preheating temperature in compound (B) preheater 12, is supplied to the reactor 13, which is heated to the reaction temperature, via compound (B) supply channel 21 from a different supply port than the second post-preheated mixture. In this way, the second post-preheated mixture and compound (B) are each supplied to the reactor 13 and mixed in the reactor 13 to obtain the post-contact mixture.

[0078] The content of the second preheating heat transfer medium in the post-contact mixture is controlled by adjusting the flow rates of compound (A), the second preheating heat transfer medium, and compound (B) using the compound (A) flow rate control device 3, the heat transfer medium flow rate control device 7, and the compound (B) flow rate control device 11, respectively. The second preheated mixture supplied to the reactor 13 mixes with compound (B) in the reactor 13 to form the post-contact mixture. The post-contact mixture is then heated in the reactor 13 at a reaction temperature of 780°C or higher, causing a reaction between the thermal decomposition products of compound (A) and compound (B), yielding a product containing HFP. In other words, the post-contact mixture is obtained by the contact of compound (A) and compound (B) in the reactor 13, and by heating and reaction, it becomes a post-reaction composition containing at least the above product and the second preheating heat transfer medium.

[0079] The post-reaction composition is supplied from the outlet of the reactor 13 through the discharge channel 14 to the washing tower 15, where it is washed with water as needed. Washing in the washing tower 15 removes the acid (e.g., hydrogen fluoride) generated by the reaction of compound (A) and compound (B) from the post-reaction composition. The post-reaction composition, after being washed as needed, is further recovered in the recovery unit 16 via the discharge channel 14. At least a portion of the post-reaction composition recovered in the recovery unit 16 is analyzed by an analyzer 17 as needed.

[0080] In another example of the manufacturing method of this embodiment using the manufacturing apparatus 100 shown in Figure 1, HFP is manufactured without using a second preheating heat transfer medium. Specifically, the HFP is manufactured in the same manner as the manufacturing method of HFP using the second preheating heat transfer medium, except that the flow rate of the second preheating heat transfer medium is set to 0 ml / min by the heat transfer medium flow rate control device 7. In this case, compound (A), which has been preheated at the first preheating temperature in the compound (A) preheater 4, passes directly through the confluence point 20 and is supplied to the reactor 13.

[0081] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 100 shown in Figure 1, the set temperature of the compound (A) preheater 4 is set to room temperature (for example, 25°C). Compound (A) reaches the confluence point 20 without being preheated in the compound (A) preheater 4. In this case, the medium contained in the heat medium container 5 becomes the first preheating heat medium. The step of mixing compound (A), which has reached the confluence point 20 without being preheated, with the first preheating heat medium heated in the heat medium heater 8 is the first preheating step described above. In another example of the manufacturing method of this embodiment using the manufacturing apparatus 100 shown in Figure 1, the set temperature of the compound (A) preheater 4 may be set to room temperature (for example, 25°C), and the flow rate of the medium contained in the heat medium container 5 may be set to 0 ml / min by the heat medium flow rate control device 7. In this case, compound (A) is supplied to the reactor 13 without being preheated. Furthermore, the set temperature of the compound (B) preheater 12 may be set to room temperature (for example, 25°C).

[0082] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 100 shown in Figure 1, a mixture of compound (A) and TFE is placed in the compound (A) container 1. The mixture of compound (A) and TFE is preheated as necessary in the compound (A) preheater 4 and the confluence point 20, respectively, and then supplied to the reactor 13.

[0083] (Other manufacturing apparatus 1) The manufacturing apparatus shown in Figure 2 is used in the manufacturing method described above, in which compound (A) is preheated in the first preheating step by heating a preheater, and the second preheated mixture obtained by mixing compound (A) with the second preheating heat transfer medium in the second preheating step is pre-mixed with compound (B) that has been preheated in the compound (B) preheating step before being supplied to the reactor. The manufacturing apparatus shown in Figure 2 may also be used in a manufacturing method in which compound (A), which has been preheated in the first preheating step by heating a preheater, is mixed directly with compound (B) without going through the second preheating step.

[0084] The manufacturing apparatus 101 shown in Figure 2 differs from the manufacturing apparatus 100 shown in Figure 1 in that, after the compound (A) supply path 18 merges with the heat transfer medium supply path 19 at the confluence point 20, the compound (A) supply path 23 further merges with the compound (B) supply path 21, which supplies compound (B) from the compound (B) preheater 12 to the confluence point 22, at the confluence point 22, becoming the compound (A) supply path 29. Other components of the manufacturing apparatus 101 shown in Figure 2, namely the compound (A) container 1, compound (A) supply channel 2, compound (A) flow rate control device 3, compound (A) preheater 4, heat transfer medium container 5, heat transfer medium supply channel 6, heat transfer medium flow rate control device 7, heat transfer medium heater 8, compound (B) container 9, compound (B) supply channel 10, compound (B) flow rate control device 11, compound (B) preheater 12, reactor 13, discharge channel 14, washing tower 15, recovery unit 16, and analysis device 17, are the same as those of the manufacturing apparatus 100 shown in Figure 1, so their explanation will be omitted.

[0085] In an example of the manufacturing method of this embodiment using the manufacturing apparatus 101 shown in Figure 2, first, compound (A) and the second preheating heat transfer medium are mixed at the confluence point 20, similar to the manufacturing method described above, to form the second preheated mixture. Next, the second preheated mixture obtained at the confluence point 20 and compound (B), which has been preheated at the compound (B) preheating temperature in the compound (B) preheater 12, are mixed at the confluence point 22 via the compound (A) supply channel 23 and the compound (B) supply channel 21, respectively, to form a post-contact mixture. The post-contact mixture obtained at the confluence point 22 is further supplied to the reactor 13, which has been heated to the reaction temperature, via the compound (A) supply channel 29.

[0086] At the confluence point 22, the second preheated mixture mixes with compound (B) to form a post-contact mixture. This post-contact mixture is then supplied to the reactor 13, where it is heated at a reaction temperature of 780°C or higher. This causes a reaction between the thermal decomposition products of compound (A) and compound (B), yielding a product containing HFP. In other words, the post-contact mixture is obtained when compound (A) and compound (B) come into contact at the confluence point 22, and the reaction through heating in the reactor 13 results in a post-reaction composition containing at least the above-mentioned product and the second preheating heat transfer medium.

[0087] In another example of the manufacturing method of this embodiment using the manufacturing apparatus 101 shown in Figure 2, HFP is manufactured without using a second preheating heat transfer medium. Specifically, for example, the flow rate of the second preheating heat transfer medium is set to 0 ml / min by the heat transfer medium flow rate control device 7, except that the HFP is manufactured in the same manner as the manufacturing method of HFP using the second preheating heat transfer medium described above. In this case, compound (A), which has been preheated at the first preheating temperature in the compound (A) preheater 4, passes through the confluence point 20 as is, and is supplied to the reactor 13 as a post-contact mixture mixed with compound (B) at the confluence point 22.

[0088] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 101 shown in Figure 2, the set temperature of the compound (A) preheater 4 is set to room temperature (for example, 25°C). Compound (A) reaches the confluence point 20 without being preheated in the compound (A) preheater 4. In this case, the medium contained in the heat medium container 5 becomes the first preheating heat medium. The step of mixing compound (A), which has reached the confluence point 20 without being preheated, with the first preheating heat medium heated in the heat medium heater 8 is the first preheating step described above. In another example of the manufacturing method of this embodiment using the manufacturing apparatus 101 shown in Figure 2, the set temperature of the compound (A) preheater 4 may be set to room temperature (for example, 25°C), and the flow rate of the medium contained in the heat medium container 5 may be set to 0 ml / min by the heat medium flow rate control device 7. In this case, compound (A) is mixed with compound (B) at the confluence point 22 without being preheated. Alternatively, the set temperature of the compound (B) preheater 12 may be set to room temperature (for example, 25°C).

[0089] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 101 shown in Figure 2, a mixture of compound (A) and TFE is placed in the compound (A) container 1. The mixture of compound (A) and TFE is preheated as necessary in the compound (A) preheater 4 and the confluence point 20, respectively, and then mixed with compound (B) at the confluence point 22.

[0090] (Other manufacturing apparatus 2) The manufacturing apparatus shown in Figure 3 is used in the manufacturing method described above, in which a post-contact mixture obtained by pre-mixing compound (A), which has been preheated by heating a preheater in the first preheating step, a contact heat transfer medium, and compound (B), which has been preheated in the compound (B) preheating step, is supplied into the reactor. The manufacturing apparatus shown in Figure 3 may also be used in a manufacturing method in which a post-contact mixture obtained by mixing compound (A) and compound (B), which have been preheated by heating a preheater in the first preheating step, without using a contact heat transfer medium, is supplied into the reactor.

[0091] The manufacturing apparatus 102 shown in Figure 3 differs from the manufacturing apparatus 100 shown in Figure 1 and the manufacturing apparatus 101 shown in Figure 2 in that the compound (A) supply path 18 merges with both the heat transfer medium supply path 19 and the compound (B) supply path 21 at the confluence point 20 to become the compound (A) supply path 23. The heat transfer medium contained in the heat transfer medium container 5 is the heat transfer medium used when compound (A) and compound (B) come into contact, and therefore differs from the manufacturing apparatus 100 shown in Figure 1 and the manufacturing apparatus 101 shown in Figure 2 in that it is a contact heat transfer medium rather than a second preheating heat transfer medium. Other components of the manufacturing apparatus 102 shown in Figure 3, namely the compound (A) container 1, compound (A) supply channel 2, compound (A) flow rate control device 3, compound (A) preheater 4, heat transfer medium container 5, heat transfer medium supply channel 6, heat transfer medium flow rate control device 7, heat transfer medium heater 8, compound (B) container 9, compound (B) supply channel 10, compound (B) flow rate control device 11, compound (B) preheater 12, reactor 13, discharge channel 14, washing tower 15, recovery unit 16, and analysis device 17, are the same as those of the manufacturing apparatus 100 shown in Figure 1, so their explanation will be omitted.

[0092] In an example of the manufacturing method of this embodiment using the manufacturing apparatus 102 shown in Figure 3, first, as in the manufacturing method described above, compound (A) is preheated at a first preheating temperature in compound (A) preheater 4, the contact heat medium is heated at the contact heat medium heating temperature in heat medium heater 8, and compound (B) is preheated at compound (B) preheating temperature in compound (B) preheater 12. Then, compound (A), the contact heat medium, and compound (B) are mixed at the confluence point 20 via compound (A) supply passage 18, heat medium supply passage 19, and compound (B) supply passage 21, respectively, to form a post-contact mixture. The post-contact mixture obtained at the confluence point 20 is further supplied to the reactor 13, which is heated to the reaction temperature, via compound (A) supply passage 23.

[0093] At the confluence point 20, compound (A), the heat transfer medium, and compound (B) are mixed to form a post-contact mixture. This post-contact mixture is then supplied to the reactor 13, where it is heated at a reaction temperature of 780°C or higher. This causes a reaction between the thermal decomposition products of compound (A) and compound (B), yielding a product containing HFP. In other words, the post-contact mixture is obtained by the contact of compound (A) and compound (B) at the confluence point 20, and the reaction through heating in the reactor 13 results in a post-reaction composition containing at least the above-mentioned product and the heat transfer medium.

[0094] In another example of the manufacturing method of this embodiment using the manufacturing apparatus 102 shown in Figure 3, HFP is manufactured without using a contact heat transfer medium. Specifically, the HFP is manufactured in the same manner as the manufacturing method of HFP using a contact heat transfer medium, except that the flow rate of the contact heat transfer medium is set to 0 ml / min by the heat transfer medium flow rate control device 7. In this case, the post-contact mixture, in which compound (A) and compound (B), preheated at a first preheating temperature in the compound (A) preheater 4, are mixed at the confluence point 20, is supplied to the reactor 13.

[0095] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 102 shown in Figure 3, the set temperature of the compound (A) preheater 4 is set to room temperature (for example, 25°C). Compound (A) reaches the confluence point 20 without being preheated in the compound (A) preheater 4 and is mixed with compound (B) and the contact heat transfer medium. In another example of the manufacturing method of this embodiment using the manufacturing apparatus 102 shown in Figure 3, the set temperature of the compound (A) preheater 4 may be set to room temperature (for example, 25°C), and the flow rate of the medium contained in the heat transfer medium container 5 may be set to 0 ml / min by the heat transfer medium flow rate control device 7. In that case, compound (A) and compound (B) are supplied to the reactor 13 without being preheated. Also, the set temperature of the compound (B) preheater 12 may be set to room temperature (for example, 25°C).

[0096] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 102 shown in Figure 3, a mixture of compound (A) and TFE is placed in the compound (A) container 1. The mixture of compound (A) and TFE is preheated in the compound (A) preheater 4, and then mixed with compound (B) at the confluence point 20.

[0097] (Other manufacturing apparatus 3) The manufacturing apparatus shown in Figure 4 is used in the manufacturing method described above, in which compound (A), a diluent, and compound (B) are mixed in advance before the preheating step, and the resulting post-contact mixture is preheated to the mixture preheating temperature by heating a preheater before being supplied to the reactor. The manufacturing apparatus shown in Figure 4 may also be used in a manufacturing method in which the post-contact mixture, obtained by mixing compound (A) and compound (B), is preheated to the mixture preheating temperature by a preheater without using a diluent.

[0098] The manufacturing apparatus 103 shown in Figure 4 includes a compound (A) container 1 for containing compound (A) before preheating, a diluent container 24 for containing a diluent medium, a compound (B) container 9 for containing compound (B) before preheating, a mixture preheater 30 for preheating the mixture after contact in the mixture preheating step, and a reactor 13 for heating compound (A) and compound (B) at the reaction temperature in the reaction step. Compound (A) supply passages 2 and 27 are provided between the compound (A) container 1 and the mixture preheater 30 to supply compound (A) from the compound (A) container 1 to the mixture preheater 30. The compound (A) supply channels 2 and 27 merge at a confluence point 28 located between the compound (A) container 1 and the mixture preheater 30. This confluence point 28 is where the diluent medium supply channel 25, which supplies the diluent medium from the diluent medium container 24 to the confluence point 28, and the compound (B) supply channel 10, which supplies compound (B) from the compound (B) container 9 to the confluence point 28. The compound (A) supply channel 2, the diluent medium supply channel 25, and the compound (B) supply channel 10 are each provided with a compound (A) flow rate control device 3 for controlling the flow rate of compound (A), a diluent medium flow rate control device 26 for controlling the flow rate of the diluent medium, and a compound (B) flow rate control device 11 for controlling the flow path of compound (B), respectively.

[0099] On the other hand, on the opposite side of the compound (A) supply passage 27 in the mixture preheater 30, a reactor 13 is provided via a compound (A) supply passage 23. On the opposite side of the compound (A) supply passage 23 in the reactor 13, a washing tower 15, a recovery unit 16, and an analysis device 17 are provided via a discharge passage 14.

[0100] In an example of the manufacturing method of this embodiment using the manufacturing apparatus 103 shown in Figure 4, compound (A) contained in compound (A) container 1, diluent contained in diluent container 24, and compound (B) contained in compound (B) container 9 are mixed at the confluence point 28 via compound (A) supply path 2, diluent supply path 25, and compound (B) supply path 10, respectively, to form a post-contact mixture. The respective contents of compound (A), compound (B), and diluent in the post-contact mixture are controlled by adjusting the flow rates of compound (A), diluent, and compound (B) using compound (A) flow rate control device 3, diluent flow rate control device 26, and compound (B) flow rate control device 11, respectively. The post-contact mixture obtained at the confluence point 28 is supplied via compound (A) supply path 27 to a mixture preheater 30 heated to the mixture preheating temperature. The post-contact mixture, heated to the preheating temperature in the mixture preheater 30, is supplied to the reactor 13, which is heated to the reaction temperature, via the compound (A) supply channel 23. In the reactor 13, the post-contact mixture is heated to the reaction temperature, causing a reaction between the thermal decomposition products of compound (A) and compound (B), yielding a product containing HFP.

[0101] In another example of the manufacturing method of this embodiment using the manufacturing apparatus 103 shown in Figure 4, HFP is manufactured without using a diluent. Specifically, for example, the HFP is manufactured in the same manner as the HFP manufacturing method using a diluent, except that the flow rate of the diluent is set to 0 ml / min by the diluent flow rate control device 26.

[0102] Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 103 shown in Figure 4, the set temperature of the mixture preheater 30 is set to room temperature (for example, 25°C). The mixture after contact is supplied to the reactor 13 without being preheated in the mixture preheater 30. In another example of the manufacturing method of this embodiment using the manufacturing apparatus 103 shown in Figure 4, the set temperature of the mixture preheater 30 may be set to room temperature (for example, 25°C), and the flow rate of the medium contained in the dilution medium container 24 may be set to 0 ml / min by the dilution medium flow rate control device 26. Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 103 shown in Figure 4, a mixture of compound (A) and TFE is contained in the compound (A) container 1. After the mixture of compound (A) and TFE is mixed with the dilution medium and compound (B) at the confluence point 28, it is preheated in the mixture preheater 30 and supplied to the reactor 13.

[0103] (Other manufacturing apparatus 4) The manufacturing apparatus shown in Figure 5 is used in the manufacturing method described above, in which a post-contact mixture obtained by pre-mixing compound (A) preheated by heating in a preheater in the first preheating step, a contact heat transfer medium, compound (B) preheated in the compound (B) preheating step, and TFE preheated in the TFE preheating step is supplied into the reactor. The manufacturing apparatus shown in Figure 5 may also be used in a manufacturing method in which a post-contact mixture obtained by mixing compound (A), compound (B), and TFE preheated by heating in a preheater in the first preheating step is supplied into the reactor without using a contact heat transfer medium.

[0104] The manufacturing apparatus 104 shown in Figure 5 differs from the manufacturing apparatus 102 shown in Figure 3 in that it further includes a TFE container 31 for storing TFE before preheating and a TFE preheater 34 for preheating the TFE. Between the TFE container 31 and the TFE preheater 34, there is a TFE supply path 32 for supplying TFE from the TFE container 31 to the TFE preheater 34, and the TFE supply path 32 is equipped with a TFE flow rate control device 33 for controlling the flow rate of TFE. At the confluence point 20, the compound (A) supply path 18 merges with the heat transfer medium supply path 19, the compound (B) supply path 21, and the TFE supply path 35 for supplying TFE from the TFE preheater 34 to the confluence point 20, forming the compound (A) supply path 23. The compound (A) container 1, compound (A) supply channel 2, compound (A) flow rate control device 3, compound (A) preheater 4, heat transfer medium container 5, heat transfer medium supply channel 6, heat transfer medium flow rate control device 7, heat transfer medium heater 8, compound (B) container 9, compound (B) supply channel 10, compound (B) flow rate control device 11, compound (B) preheater 12, reactor 13, discharge channel 14, washing tower 15, recovery unit 16, and analysis device 17 of the manufacturing apparatus 104 shown in Figure 5 are the same as those of the manufacturing apparatus 102 shown in Figure 3, so their explanation is omitted.

[0105] In an example of the manufacturing method of this embodiment using the manufacturing apparatus 104 shown in Figure 5, first, as in the manufacturing method described above, compound (A) is preheated at a first preheating temperature in compound (A) preheater 4, the contact heat medium is heated at the contact heat medium heating temperature in heat medium heater 8, and compound (B) is preheated at compound (B) preheating temperature in compound (B) preheater 12. Also, TFE is preheated at TFE preheating temperature in TFE preheater 34. Then, compound (A), the contact heat medium, compound (B), and TFE are mixed at the confluence point 20 via compound (A) supply passage 18, heat medium supply passage 19, compound (B) supply passage 21, and TFE supply passage 35, respectively, to form a post-contact mixture. The post-contact mixture obtained at the confluence point 20 is further supplied to the reactor 13, which is heated to the reaction temperature, via compound (A) supply passage 23.

[0106] At the confluence point 20, compound (A), the heat transfer medium, compound (B), and TFE are mixed to form a post-contact mixture. This post-contact mixture is then supplied to the reactor 13, where it is heated at a reaction temperature of 780°C or higher. This causes the thermal decomposition products of compound (A) and compound (B) to react with TFE, yielding a product containing HFP. In other words, the post-contact mixture is obtained when compound (A), compound (B), and TFE come into contact at the confluence point 20, and the reaction through heating in the reactor 13 results in a post-reaction composition containing at least the above-mentioned product and the heat transfer medium.

[0107] In another example of the manufacturing method of this embodiment using the manufacturing apparatus 104 shown in Figure 5, HFP may be manufactured without using a contact heat transfer medium, similar to the manufacturing apparatus 102 shown in Figure 3. Also, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 104 shown in Figure 5, the set temperature of the compound (A) preheater 4 may be set to room temperature (for example, 25°C), similar to the manufacturing apparatus 102 shown in Figure 3. Furthermore, in another example of the manufacturing method of this embodiment using the manufacturing apparatus 104 shown in Figure 5, the set temperature of the compound (A) preheater 4 may be set to room temperature (for example, 25°C), and the flow rate of the medium contained in the heat transfer medium container 5 may be set to 0 ml / min by the heat transfer medium flow rate control device 7. Also, the set temperature of the compound (B) preheater 12 may be set to room temperature (for example, 25°C), and the set temperature of the TFE preheater 34 may be set to room temperature (for example, 25°C).

[0108] The embodiments of this disclosure will be described in detail below with reference to examples, but the embodiments of this disclosure are not limited to these.

[0109] [Example 4, 19-20] Using the manufacturing apparatus 100 shown in Figure 1, a product containing hexafluoropropene (HFP) was obtained using trifluoromethane (R23), octafluorocyclobutane (C318), and nitrogen gas as a second preheating heat transfer medium by the method described below.

[0110] Trifluoromethane (R23) was supplied from compound (A) container 1 to compound (A) preheater 4, which was set to the first preheating temperature shown in the table ("Preheating temperature / Heating temperature (°C) R23" in the table), via compound (A) supply path 2. Meanwhile, nitrogen gas was supplied from heat transfer medium container 5 to the heat transfer medium heating temperature shown in the table ("Preheating temperature / Heating temperature (°C) N23" in the table). ２ The compound (C) was supplied to the heat transfer medium heater 8, which was set to the specified temperature, via the heat transfer medium supply passage 6. In addition, octafluorocyclobutane (C318) was supplied from the compound (C) container 9 to the compound (C) preheater 12, which was set to the compound (C) preheating temperature shown in the table (in the table, "Preheating temperature / Heating temperature (°C) C318"), via the compound (C) supply passage 10.

[0111] The compound (A) R23, preheated in the compound (A) preheater 4, and the nitrogen gas, heated in the heat transfer medium heater 8, were mixed at the confluence point 20 of the compound (A) supply channel 18 and the heat transfer medium supply channel 19 to obtain a second preheated mixture. The obtained second preheated mixture and the compound (B) C318, preheated in the compound (B) preheater 12, were supplied to the reactor 13, controlled to the reaction temperature and gauge pressure values ​​shown in the table, via the compound (A) supply channel 23 and the compound (B) supply channel 21, respectively. The reaction time, i.e., the residence time in the reactor 13, is shown in the table.

[0112] The flow rates of R23, nitrogen gas, and C318 were adjusted using the compound (A) flow rate control device 3, the heat transfer medium flow rate control device 7, and the compound (B) flow rate control device 11, respectively. By adjusting the flow rates of R23, nitrogen gas, and C318 as described above, the supply amounts of R23, nitrogen gas, and C318 supplied to the reactor 13 per unit time were controlled to the values ​​shown in the table.

[0113] The outlet gas (post-reaction composition) discharged from reactor 13 contained not only the products generated by the reaction but also unreacted raw materials R23 and C318. The post-reaction composition was supplied to washing tower 15 via discharge channel 14. In washing tower 15, the post-reaction composition was washed with distilled water to remove acid. The post-reaction composition, from which the acid had been removed, was recovered in recovery unit 16, and the recovered post-reaction composition was analyzed in analyzer 17. The analyzer 17 used a gas chromatograph (product name "GC-2014", manufactured by Shimadzu Corporation) and a capillary column (product name "PoraPLOT Q", manufactured by Agilent).

[0114] Based on the analysis of the composition of the post-reaction composition using the analytical instrument 17, the content of the raw materials R23 and C318, the reaction intermediate TFE, and the target product HFP was calculated relative to the total components of the post-reaction composition excluding the heat transfer medium nitrogen gas. Specifically, the calculations were performed based on the relative sensitivity of each component in gas chromatography. The amount of R23, TFE, HFP, and C318 discharged per unit time was determined from the amount of post-reaction composition discharged from the reactor per unit time, the proportion of nitrogen gas contained in the post-reaction composition, and the proportion of each component obtained from the analysis results of the analytical instrument 17. The results are shown in the table. The table also shows the HFP production efficiency calculated from the supply and discharge amounts of each component using the method described above.

[0115] [Examples 3, 5-18, 21-22, 36] Except that nitrogen gas, the second heat transfer medium for preheating, was not used, the amount of R23 and C318 supplied to the reactor 13 per unit time, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R23" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) C318" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 4, and the content of R23, C318, TFE, and HFP relative to the total components of the post-reaction composition excluding nitrogen gas was calculated. The table shows the amount of R23, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, calculated in the same manner as in Example 4.

[0116] [Example 35] A post-reaction composition was obtained in the same manner as in Example 4, except that C318 and nitrogen gas were not used, and the amount of R23 supplied to the reactor 13 per unit time, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R23" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 4, and the content of R23, C318, TFE, and HFP relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, which were calculated in the same manner as in Example 4.

[0117] [Example 2] A post-reaction composition was obtained in the same manner as in Example 4, except that R22 was used instead of R23 as the raw material gas contained in compound (A) container 1, nitrogen gas was not used, and the supply amounts of R22 and C318 supplied to reactor 13 per unit time, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R22" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) C318" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 4, and the content of R22, C318, TFE, and HFP relative to the total components of the post-reaction composition excluding nitrogen gas was calculated. The table shows the amount of R22, TFE, HFP, and C318 discharged per unit time and the HFP production efficiency, calculated in the same manner as in Example 4.

[0118] [Example 1] A post-reaction composition was obtained in the same manner as in Example 2, except that C318 and nitrogen gas were not used, and the amount of R22 supplied to the reactor 13 per unit time, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R22" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 2, and the content of R22, C318, TFE, and HFP relative to the entire post-reaction composition was calculated. The table shows the amount of R22, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, which were calculated in the same manner as in Example 2.

[0119] [Example 25] Using the manufacturing apparatus 102 shown in Figure 3, a product containing hexafluoropropene (HFP) was obtained using trifluoromethane (R23) and octafluorocyclobutane (C318) by the method described below.

[0120] Trifluoromethane (R23) was supplied from compound (A) container 1 to compound (A) preheater 4, which was set to the first preheating temperature shown in the table ("Preheating temperature / Heating temperature (°C) R23" in the table), via compound (A) supply path 2. In addition, octafluorocyclobutane (C318) was supplied from compound (B) container 9 to compound (B) preheater 12, which was set to the compound (B) preheating temperature shown in the table ("Preheating temperature / Heating temperature (°C) C318" in the table), via compound (B) supply path 10.

[0121] R23, preheated in compound (A) preheater 4, and C318, preheated in compound (B) preheater 12, were mixed at the confluence point 20 of compound (A) supply channel 18 and compound (B) supply channel 21 to obtain a post-contact mixture. The obtained post-contact mixture was supplied via compound (A) supply channel 23 to reactor 13, which was controlled to the reaction temperature and gauge pressure values ​​shown in the table. The reaction time, i.e., the residence time in reactor 13, is shown in the table. The flow rates of R23 and C318 were adjusted using compound (A) flow rate control device 3 and compound (B) flow rate control device 11, respectively. By adjusting the flow rates of R23 and C318 as described above, the amount of R23 and C318 supplied to reactor 13 per unit time was controlled to the values ​​shown in the table.

[0122] The outlet gas (post-reaction composition) discharged from reactor 13 contained not only the products generated by the reaction but also unreacted raw materials, R23 and C318. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 4, and the content of R23, C318, TFE, HFP, and the by-product R1225ye relative to the total post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, C318, and R1225ye discharged per unit time and the HFP generation efficiency, calculated in the same manner as in Example 4. The table also shows the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the post-reaction composition (molar amount of HFP / molar amount of R1225ye).

[0123] [Example 24] Using the manufacturing apparatus 103 shown in Figure 4, a product containing hexafluoropropene (HFP) was obtained using trifluoromethane (R23), octafluorocyclobutane (C318), and nitrogen gas as a diluent, by the method described below.

[0124] Trifluoromethane (R23), nitrogen gas, and octafluorocyclobutane (C318) were supplied from compound (A) container 1, diluent container 24, and compound (B) container 9, respectively, and mixed at the confluence point 28 to obtain a post-contact mixture. The obtained post-contact mixture was supplied via compound (A) supply channel 27 to a mixture preheater 30 set to the mixture preheating temperature (preheating temperature / heating temperature (°C) in the table) shown in the table. Subsequently, it was supplied via compound (A) supply channel 23 to a reactor 13 controlled to the reaction temperature and gauge pressure values ​​shown in the table. The reaction time, i.e., the residence time in reactor 13, is shown in the table. The flow rates of R23, nitrogen gas, and C318 were adjusted using compound (A) flow rate control device 3, diluent container flow rate control device 26, and compound (B) flow rate control device 11, respectively. By adjusting the flow rates of R23, nitrogen gas, and C318 as described above, the amount of R23, nitrogen gas, and C318 supplied to the reactor 13 per unit time was controlled to the values ​​shown in the table.

[0125] The outlet gas (post-reaction composition) discharged from reactor 13 contained not only the products generated by the reaction but also unreacted raw materials, R23 and C318. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 4, and the content of R23, C318, TFE, and HFP relative to the total components of the post-reaction composition excluding nitrogen gas was calculated. The table shows the amount of R23, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, calculated in the same manner as in Example 4.

[0126] [Example 23] Except that nitrogen gas, which is used as a diluent, was not used, and the supply amounts of R23 and C318 supplied to the reactor 13 per unit time, the preheating temperature of the mixture ("Preheating temperature / Heating temperature (°C)" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table, a post-reaction composition was obtained in the same manner as in Example 24. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 24, and the content of R23, C318, TFE, and HFP in the total post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, which were calculated in the same manner as in Example 24.

[0127] [Example 26] The post-reaction composition was obtained in the same manner as in Example 23, except that R125 was used instead of C318 as the raw material gas contained in the compound (B) container 9, nitrogen gas was not used, and the supply amounts of R23 and R125 supplied to the reactor 13 per unit time, the preheating temperature of the mixture ("Preheating temperature / Heating temperature (°C)" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 23, and the content of R23, R125, TFE, and HFP, as well as the by-product R1225ye, relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, R125, and R1225ye discharged per unit time and the HFP production efficiency, calculated in the same manner as in Example 23. The table also shows the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the post-reaction composition (molar amount of HFP / molar amount of R1225ye).

[0128] [Example 31] A post-reaction composition was obtained in the same manner as in Example 23, except that a mixture of R23 and TFE was used instead of R23 alone as the raw material gas contained in compound (A) container 1, nitrogen gas was not used, and the supply amounts of R23, TFE, and C318 per unit time to reactor 13, the first preheating temperature and TFE preheating temperature ("Preheating temperature / Heating temperature (°C) R23" and "Preheating temperature / Heating temperature (°C) TFE" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) C318" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 23, and the content of R23, C318, TFE, HFP, and the by-product R1225ye relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, C318, and R1225ye discharged per unit time, as well as the HFP generation efficiency, calculated in the same manner as in Example 23. The table also shows the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the post-reaction composition (moles of HFP / molar amount of R1225ye).

[0129] [Example 33] Using the manufacturing apparatus 104 shown in Figure 5, a product containing hexafluoropropene (HFP) was obtained using trifluoromethane (R23), octafluorocyclobutane (C318), tetrafluoroethylene (TFE), and nitrogen gas as a heat transfer medium in the following manner.

[0130] Trifluoromethane (R23) was supplied from compound (A) container 1 to compound (A) preheater 4, which was set to the first preheating temperature shown in the table ("Preheating temperature / Heating temperature (°C) R23" in the table), via compound (A) supply path 2. Meanwhile, nitrogen gas was supplied from heat transfer medium container 5 to heat transfer medium heater 8, which was set to the heat transfer medium heating temperature shown in the table, via heat transfer medium supply path 6. In addition, octafluorocyclobutane (C318) was supplied from compound (B) container 9 to compound (B) preheater 12, which was set to the compound (B) preheating temperature shown in the table ("Preheating temperature / Heating temperature (°C) C318" in the table), via compound (B) supply path 10. In addition, TFE container 31 was supplied to the TFE preheating temperature shown in the table ("Preheating temperature / Heating temperature (°C) R23" in the table) Tetrafluoroethylene (TFE) was supplied to the TFE preheater 34, which was set to TFE, via the TFE supply passage 32.

[0131] R23 preheated in compound (A) preheater 4, nitrogen gas heated in heat transfer medium heater 8, C318 preheated in compound (B) preheater 12, and TFE preheated in TFE preheater 34 were mixed at the confluence point 20 of compound (A) supply channel 18, heat transfer medium supply channel 19, compound (B) supply channel 21, and TFE supply channel 35 to obtain a post-contact mixture. The obtained post-contact mixture was supplied via compound (A) supply channel 23 to reactor 13, which was controlled to the reaction temperature and gauge pressure values ​​shown in the table. The reaction time, i.e., the residence time in reactor 13, is shown in the table. The flow rates of R23, nitrogen gas, C318, and TFE were adjusted using compound (A) flow rate control device 3, heat transfer medium flow rate control device 7, compound (B) flow rate control device 11, and TFE flow rate control device 33, respectively. By adjusting the flow rates of R23, nitrogen gas, C318, and TFE as described above, the supply amounts of R23, nitrogen gas, C318, and TFE supplied to the reactor 13 per unit time were controlled to the values ​​shown in the table.

[0132] The outlet gas (post-reaction composition) discharged from reactor 13 contained not only the products generated by the reaction but also unreacted raw materials R23, C318, and TFE. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 4, and the content of R23, C318, TFE, and HFP relative to the total post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, calculated in the same manner as in Example 4.

[0133] [Example 27] Except that nitrogen gas, which is used as a diluent, was not used, and the supply amounts of R23, TFE, and C318 supplied to the reactor 13 per unit time, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R23" in the table), the TFE preheating temperature ("Preheating temperature / Heating temperature (°C) TFE" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) C318" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table, a post-reaction composition was obtained in the same manner as in Example 33. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 33, and the content of R23, C318, TFE, HFP, and the by-product R1225ye relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, C318, and R1225ye discharged per unit time, as well as the HFP generation efficiency, calculated in the same manner as in Example 33. The table also shows the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the post-reaction composition (moles of HFP / molar amount of R1225ye).

[0134] [Examples 28, 29, 34] Except that nitrogen gas was not used as a diluent, the amount of R23, TFE, and C318 supplied to the reactor 13 per unit time, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R23" in the table), the TFE preheating temperature ("Preheating temperature / Heating temperature (°C) TFE" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) C318" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 33, and the content of R23, C318, TFE, and HFP relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, and C318 discharged per unit time and the HFP generation efficiency, which were calculated in the same manner as in Example 33.

[0135] [Example 30] A post-reaction composition was obtained in the same manner as in Example 27, except that R125 was used instead of C318 as the raw material gas contained in the compound (B) container 9, nitrogen gas was not used, and the supply amounts of R23, TFE, and R125 per unit time to the reactor 13, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R23" in the table), the TFE preheating temperature ("Preheating temperature / Heating temperature (°C) TFE" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) R125" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 27, and the content of R23, R125, TFE, HFP, and the by-product R1225ye relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, R125, and R1225ye discharged per unit time, as well as the HFP generation efficiency, calculated in the same manner as in Example 27. The table also shows the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the post-reaction composition (moles of HFP / molar amount of R1225ye).

[0136] [Example 32] The post-reaction composition was obtained in the same manner as in Example 27, except that R125 was placed in place of nitrogen gas in the heat transfer medium container 5, and the supply amounts of R23, TFE, C318, and R125 per unit time supplied to the reactor 13, the first preheating temperature ("Preheating temperature / Heating temperature (°C) R23" in the table), the TFE preheating temperature ("Preheating temperature / Heating temperature (°C) TFE" in the table), the compound (B) preheating temperature ("Preheating temperature / Heating temperature (°C) C318" and "Preheating temperature / Heating temperature (°C) R125" in the table), the reaction temperature, the gauge pressure in the reactor, and the reaction time were set to the values ​​shown in the table. The composition of the obtained post-reaction composition was analyzed in the same manner as in Example 27, and the content of R23, C318, R125, TFE, and HFP, as well as the by-product R1225ye, relative to the entire post-reaction composition was calculated. The table shows the amount of R23, TFE, HFP, C318, R125, and R1225ye discharged per unit time, as well as the HFP generation efficiency, calculated in the same manner as in Example 27. The table also shows the ratio of the molar amount of HFP to the molar amount of R1225ye contained in the post-reaction composition (moles of HFP / molar amount of R1225ye).

[0137] Note that all of the above examples were conducted in an environment where the room temperature was 25°C. Also, the reactors used in all of the above examples were not filled with catalyst. In Tables 1 to 7 below, when the notation for "Preheating temperature / Heating temperature (°C)" is 25°C, it means that the preheater was set to 25°C and no preheating was performed. In Tables 1 to 7 below, "-" means that the corresponding component was not used.

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145] In the above examples, Examples 1 and 3-34 are examples, and Examples 2 and 35-36 are comparative examples. As shown in Table 1, it can be seen that Example 1 has a higher HFP generation efficiency than Example 2. Similarly, it can be seen that Examples 3-34 have a higher HFP generation efficiency than Examples 35-36. Furthermore, it can be seen that Examples 26 and 30 produce less R1225ye than Examples 25, 27, 31, and 32. In addition, it can be seen that Examples 26, 30, and 32 have a higher HFP molar amount / R1225ye molar amount value than Examples 25, 27, and 31.

[0146] The disclosure of Japanese Patent Application No. 2024-205763, filed on 26 November 2024, is incorporated herein by reference in its entirety. Furthermore, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated as being incorporated by reference.

[0147] 1 Compound (A) container 2 Compound (A) supply channel 3 Compound (A) flow rate control device 4 Compound (A) preheater 5 Heat transfer medium container 6 Heat transfer medium supply channel 7 Heat transfer medium flow rate control device 8 Heat transfer medium heater 9 Compound (B) container 10 Compound (B) supply channel 11 Compound (B) flow rate control device 12 Compound (B) preheater 13 Reactor 14 Discharge channel 15 Washing tower 16 Recovery unit 17 Analytical device 18, 23, 27, 29 Compound (A) supply channel 19 Heat transfer medium supply channel 20, 22, 28 Confluence point 21 Compound (B) supply channel 24 Dilution medium container 25 Dilution medium supply channel 26 Dilution medium flow rate control device 30 Mixture preheater 31 TFE container 32, 35 TFE supply channel 33 TFE flow control device 34 TFE preheater 100, 101, 102, 103, 104 Manufacturing equipment

Claims

1. A method for producing hexafluoropropene, comprising contacting a compound (A) represented by the following formula (A) with a compound (B) which is at least one selected from the group consisting of octafluorocyclobutane, pentafluoroethane, octafluoro-1-butene, and octafluoro-2-butene, and heating the resulting mixture in a reactor at a reaction temperature of 780°C or higher to obtain a product containing hexafluoropropene. (A) CHF ２ -X In formula (A), X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

2. The method for producing hexafluoropropene according to claim 1, wherein the post-contact mixture is a mixture obtained by contacting compound (A), tetrafluoroethylene, and compound (B).

3. The method for producing hexafluoropropene according to claim 1, wherein the post-contact mixture is a mixture obtained by contacting compound (A) with tetrafluoroethylene and compound (B) with nitrogen.

4. The method for producing hexafluoropropene according to any one of claims 1 to 3, wherein the compound (A) comprises at least one selected from the group consisting of chlorodifluoromethane and trifluoromethane.

5. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein compound (A) is trifluoromethane and compound (B) is at least one selected from the group consisting of octafluorocyclobutane and pentafluoroethane.

6. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein compound (A) is trifluoromethane and compound (B) is octafluorocyclobutane and pentafluoroethane.

7. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein compound (A) is trifluoromethane and compound (B) is pentafluoroethane.

8. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein compound (A) is trifluoromethane and compound (B) is octafluorocyclobutane.

9. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein the contacted mixture is preheated at a mixture preheating temperature of less than 780°C, and then heated in the reactor at the reaction temperature.

10. The method for producing hexafluoropropene according to claim 9, wherein the preheating temperature of the mixture is 100 to 750°C.

11. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein the compound (A) is preheated at a first preheating temperature of less than 780°C before the contact.

12. The method for producing hexafluoropropene according to claim 11, wherein the first preheating temperature is 100 to 750°C.

13. The method for producing hexafluoropropene according to claim 11, wherein, prior to the contact, compound (A) preheated at the first preheating temperature is mixed with a second preheating heat medium heated at a second preheating heat medium heating temperature that is higher than the first preheating temperature but less than 780°C to obtain a second post-preheated mixture.

14. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein before the contact, compound (B) is preheated at a compound (B) preheating temperature of 100 to 350°C.

15. The method for producing hexafluoropropene according to claim 11, wherein before the contact, compound (B) is preheated at a compound (B) preheating temperature of 100 to 350°C.

16. The method for producing hexafluoropropene according to claim 13, wherein, prior to the contact, compound (B) is preheated at a compound (B) preheating temperature of 100 to 350°C.

17. The method for producing hexafluoropropene according to any one of claims 1 to 3, wherein the reaction temperature is 800 to 1000°C.

18. A method for producing hexafluoropropene according to any one of claims 1 to 3, wherein the heating time at the reaction temperature is 2 seconds or less.

19. The method for producing hexafluoropropene according to any one of claims 1 to 3, wherein the reactor is not filled with a catalyst inside.

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